Process of making metal road studs



A ril 23, 1935. e. BENEDETTO PROCESS OF MAKING METAL ROAD STUDS Filed June 11, 1934 1312 HI) eys Patented Apr. 23, 1935 UNITED STATES PROCESS OF MAKING METAL ROAD STUDS Giuseppe Benedetto, Novara, Italy, assignor to Omes Holding Company Limited, London, England, a British company Application June 11, 1934, Serial No. 130,110 In Great Britain June 6, 1933 2 Claims.

quently embedded in the surface of roads for the purpose of affording guidance to traffic as to the lines along which it may proceed.

Hitherto metal blocks or studs let into the surface of the road have been constructed of cast metal or of stainless steel, but stainless steel studs produced by ordinary casting or forging operations are expensive and metal castings are bulky and diilicult to fix.

The present invention deals particularly with the formation of a road stud having the form of a large flattened head portion and a stem integral therewith projecting downwardly from the underside of the head portion so as to enter into the material of the road.

Further, according to the presentinvention a method of making a road stud consists in taking a bar of metal of a diameter equal to that desired for a stem portion and forming a broad flat head on the end thereof by forging in an electrical upsetting machine, preferably with subsequent pressing in a die-stamp.

The accompanying drawing illustrates by way of example various kinds of studs in accordance with the present invention, and in the drawing:-

Figure l is a side elevation of one form' of stud;

Figure 2 is a perspective view of the same stud upside down to show the underside;

Figure 3 is a side elevation of a second form;

Figure 4 is a view similar to Figure 2 of the form shown in Figure 3, and

Figure 5 is a perspective view of the upper side of a third form of stud.

Referring to Figures 1 and 2 the stud comprises a stem II and a broad flat head I2 square as viewed in plan and convex on its upper side. The underside is concave as indicated at l3 and is provided with four downwardly projecting studs or nibs M which are intended to enter the road surface and prevent the head from turning relatively thereto about the stem II.

Referring to Figures 3 and 4, these show a stud having a stem i5 and a convex circular head It, the underside of which is hollow as shown at H and provided with radial ribs I8 which not only stiffen the convex head portion but also serve to key the stud against rotation relatively to the road surface. In addition the stem I5 is split and splayed at its bottom end by cutting it longitudinally in a. shearing machine for a certain distance, resulting in two inclined portions l9 similar to the end of a rag-bolt. These afford an additional key against rotation or lifting of the stud.

Figure 5 illustrates a stud-comprising a threecornered head portion 20 on a stem 2| the bottom end of which is split and splayed at 22 as already described. In the centre of the head portion there is an embossed letter 23. Studs of this kind can be set in a road surface so that'they point towards a parking place and lead the motorist to the entrance thereof. Conveniently such studs may be formed from metal of a distinctive colour, such as bronze.

The method of manufacture of the studs illustrated may comprise first taking a bar of a diameter equal to that of the stem of the stud, then upsetting (in an electrical forging machine such, for example, as that described in prior United States Patent No. 1,878,810) a head containing a sufficiency of metal to constitute the head of the finished stud and finally shaping this head in a dieor drop-stamp while the metal is still hot from the electric forging operation. The amount of metal in the head may be as much as corresponds to about fifteen diameters of the stem. If steel is employed it is preferable to use stainless steel. The head can then be polished after forging.

It will be observed that by following the procedure outlined in my prior patent referred to, the stud is formed to provide a dense forged structure in which the grain runs longitudinally along the shank and is bent round in the head so that the fibre of the metal extends parallel with the upper and lower surfaces. If one of the road studamanufactured as described in my prior 3 patent, be cut in half and the sectioned surface be etched with acid the lines of flow of the metal will be seen to follow the course just described. This is due to the method of forging, and results in a stud much more durable and stronger than those produced by casting. Thus the fibre of the metal lies parallel to the upper surface of the stud and takes the wear in traflic. At the same time the method of forging adopted permits the production of downward projections from the underside of the head into which the metal is caused to flow by the stamping operation, the fibre of the metal again extending parallel to the length of the projections or ribs to lend additional strength thereto.

Alternatively non-ferrous metal such as aluminium or copper or alloys of aluminium or copper may be employed; the alloys may include brass, Monel metal, bronzes in general or other alloys of copper with tin, nickel, aluminium or zinc.

A convenient diameter or stem using a nonferrous metal is fiths of an inch diameter and the head may be conveniently about four inches across. Instead of splitting and splaying the bottom end of the stem a head may be upset thereon if desired and then flattened in a plane parallel to the stem.

I claim:

1. A method of making road studs which comprises forming on one end of a bar of non-ferrous metal of a diameter equal to that desired for a stem portion, a broad fiat head by first heating the end of the bar and applying pressure thereto in the direction of the length 01' the bar, whereby the grain in the head of the stud may extend generally radially and the grain in the stem may extend generally longitudinally, subbar, whereby the grain in the head of the stud may extend generally radially and the grain in the stem may extend generally longitudinally, subsequently pressing the head to final shape in a die stamp, and splitting and splaying that end of the stem remote from the head to increase a lateral dimension thereof.

GIUSEPPE BENEDE'TTO. 

